A coating material composed of metal flakes such as aluminum flakes and a coloring pigment is generally employed for providing glossiness in metallic coating applied to a mechanical product or a plastic product. In particular, a colored flake pigment comprising a metallic flake pigment and a coloring pigment bonded thereto, has excellent performance in such points that a vivid color tone can be obtained and concealment of a base color is excellent. An organic pigment such as a diketopyrrolopyrrole-based pigment, a quinacridone-based pigment, a dioxazine-based pigment, an isoindolinone-based pigment, a condensed azo-based pigment, a threne-based pigment, a perynone-based pigment, a perylene-based pigment, a quinophthalone-based pigment or a phthalocyanine-based pigment or an inorganic pigment such as iron oxide or carbon black is used for such a colored flake pigment.
For example, Japanese Patent Laying-Open No. 58-141248 (Patent Document 1) proposes a colored metallic pigment prepared by homogeneously bonding a coloring pigment to the surface of a metallic pigment with a polymer composed of a monomer having polymerizable double bonds, National Patent Publication Gazette No. 5-508424 (Patent Document 2) proposes a colored pigment composed of a combination of fragments of metal and a polymer matrix held thereon for pocketing a solid colorant in particular, Japanese Patent Laying-Open No. 1-315470 (Patent Document 3) proposes a primary colored metallic pigment prepared by chemisorbing a coloring pigment onto the surface of a metallic pigment through carboxylic acid having at least one double bond and at least two carboxyl groups obtained by thermally polymerizing at least one carboxylic acid having double bonds, Japanese Patent Laying-Open No. 9-40885 (Patent Document 4) proposes a surface treated colored pigment prepared by covering the surface of a colored pigment with 0.2 to 100 parts by weight of monobasic aromatic carboxylic acid with respect to 100 parts by weight of the colored pigment, Japanese Patent Laying-Open No. 9-59532 (Patent Document 5) proposes a colored metallic flake pigment having an evaporated layer of an organic coloring pigment on the surface thereof and Japanese Patent Laying-Open No. 9-124973 (Patent Document 6) proposes a surface treated colored pigment prepared by covering the surface of a colored pigment with 0.2 to 100 parts by weight of an amino compound having two amino groups in each molecule with no carboxyl group with respect to 100 parts of the colored pigment respectively.
However, each of these colored metallic flake pigments has such a problem that the coloring pigment bonded to the surface is easily photo-deteriorated due to reflection of light on the surface of the pigment composed of aluminum or the like. Particularly in the color gamuts of yellow and red, it has been difficult to obtain a colored aluminum pigment having both of weather resistance and designability.    Patent Document 1: Japanese Patent Laying-Open No. 58-141248    Patent Document 2: National Patent Publication Gazette No. 5-508424    Patent Document 3: Japanese Patent Laying-Open No. 1-315470    Patent Document 4: Japanese Patent Laying-Open No. 9-40885    Patent Document 5: Japanese Patent Laying-Open No. 9-59532    Patent Document 6: Japanese Patent Laying-Open No. 9-124973